Octal bus transceiver with hot insertion and bus-hold

August 05, 2016 // By Graham Prophet
The 74LVT245BB octal transceiver (Diodes Inc.) enables asynchronous communication between data buses. A control pin determines data flow direction, while disabling the tri-state outputs allows the buses to be completely isolated.

The 74LVT245BB adds a partial power-down capability to the normal asynchronous communication between data buses. This disables the outputs and prevents damaging current backflow when the device is powered down. It also withstands hot insertion by maintaining the tri-state output during power-up. Schmitt trigger action inputs also include a bus-hold feature so no resistors are required on unused inputs. Combined with a latch-up immunity of better than 500 mA, these transceivers enable board designs that can be hot-swapped in applications such as computer servers and cell phone base stations without the need to turn equipment off.

Operation of the 74LVT245BB is specified for a supply voltage range of 2.7V to 3.6V and inputs can be driven at 3.3V or 5V, allowing for mixed-logic voltage applications. Outputs can sink 64 mA or source 32 mA and have leakage current of <125 μA when forced to 5.5V. With a 2.7 nsec (typical) propagation time, a drive capability suitable for large bus architectures, and the ability to power down to avoid loading the data bus, the 74LVT245BB offers gains in power performance ratio, reliability and cost.

In TSSOP-20 and the smaller QFN-20 package, the 74LVT245BB is priced at $0.21 (2500).

Diodes: www.diodes.com